Battling sleeping sickness

I thought it was a great story, and so it also features in this weeks’ Science in Action (which I produced!) and is first broadcast today at 18:32 GMT.

The story is quite tough, and for someone who has absolutely no idea about parasitology, immunology or anything in that field, I needed several metaphors to get my head around it.

So, for anyone reading or listening to this story, here is how I got my head around it:

Sleeping sickness is a big problem in Africa, especially in central and western areas. It’s caused by parasites from the trypanosma family, which are transmitted in the bites of tsetse flies.

Over the many many years, humans have evolved a natural antidote to this parasite in most cases, but two strains (Rhodensiense and Gambiense) have managed to over come our natural defences, which is why it still remains a problem. It’s an arms race: who can evolve the best defences the quickest?

A few years back, Etienne Pays and his team in Brussels figured out how Rhodensiense fights back against our antidotes: they somehow manage to disengage our proteins, and thus we can’t fight back.

This year, the very same team figured out how Gambiense fights back, and it’s in a completely different way. There are three stages to it’s defence (this is where the metaphor comes in):

1) Gambiense has invented a protein that stiffens the walls of the membranes lining the digestive system, so our antidote cannot penetrate them. AKA: Gambiense builds a fortress to stop our team coming in.

2) If, somehow, our antidote does make it through, Gambiense has developed an extremely efficient absorption process, so our antidote cannot reach as far as